//
// Created by francklinson on 2021/12/4 AT 9:55.
// May Saint Diana bless you!
//

#include <iostream>
#include <vector>
#include <unordered_map>
#include <unordered_set>
#include <queue>
#include <algorithm>
#include <functional>
#include <climits>
#include <string>

using namespace std;

class Solution {
public:
    int countOdds(int low, int high) {
        int length = high - low + 1;
        if (length % 2 == 0) {
            return length / 2;
        } else {
            return length / 2 + (low % 2 == 1 ? 1 : 0);
        }
    }
};

int main() {
    Solution solution;
    cout << solution.countOdds(3, 7) << endl;
    return 0;
}

